Sometimes, the notification of missing mfc100.dll file comes in a computer due to an error. Some applications do not work properly due to the missing of this file on the PC. It causes due to a hardware failure or the installation of any harmful program. It is highly recommended to MS Visual C++ SP1 to overcome this issue. Sometimes, you deleted this file mistakenly which can be restored from recycle bin. In case of emptying recycle bin, you can use free file recovery software for getting it back. A deep scan of a system is also a good solution to get a missing mfc100.dll file. You can also download mfc100.dll file missing from Windows 7 from here for free.